/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.connector;

import java.io.IOException;
import java.io.UnsupportedEncodingException;

import org.apache.catalina.CometEvent;
import org.apache.catalina.Context;
import org.apache.catalina.Globals;
import org.apache.catalina.Wrapper;
import org.apache.catalina.util.StringManager;
import org.apache.catalina.util.ServerInfo;
import org.apache.catalina.util.URLEncoder;
import org.apache.coyote.ActionCode;
import org.apache.coyote.Adapter;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.buf.B2CConverter;
import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.CharChunk;
import org.apache.tomcat.util.buf.MessageBytes;
import org.apache.tomcat.util.http.Cookies;
import org.apache.tomcat.util.http.ServerCookie;
import org.apache.tomcat.util.net.SocketStatus;

/**
 * Implementation of a request processor which delegates the processing to a
 * Coyote processor.
 * 
 * @author Craig R. McClanahan
 * @author Remy Maucherat
 * @version $Id: CoyoteAdapter.java 1149220 2011-07-21 15:23:11Z markt $
 */

public class CoyoteAdapter implements Adapter {

	private static Log log = LogFactory.getLog(CoyoteAdapter.class);

	// -------------------------------------------------------------- Constants

	private static final String POWERED_BY = "Servlet/2.5 JSP/2.1 " + "("
			+ ServerInfo.getServerInfo() + " Java/"
			+ System.getProperty("java.vm.vendor") + "/"
			+ System.getProperty("java.runtime.version") + ")";

	public static final int ADAPTER_NOTES = 1;

	protected static final boolean ALLOW_BACKSLASH = Boolean
			.valueOf(
					System
							.getProperty(
									"org.apache.catalina.connector.CoyoteAdapter.ALLOW_BACKSLASH",
									"false")).booleanValue();

	// ----------------------------------------------------------- Constructors

	/**
	 * Construct a new CoyoteProcessor associated with the specified connector.
	 * 
	 * @param connector
	 *            CoyoteConnector that owns this processor
	 */
	public CoyoteAdapter(Connector connector) {

		super();
		this.connector = connector;

	}

	// ----------------------------------------------------- Instance Variables

	/**
	 * The CoyoteConnector with which this processor is associated.
	 */
	private Connector connector = null;

	/**
	 * The string manager for this package.
	 */
	protected StringManager sm = StringManager.getManager(Constants.Package);

	/**
	 * Encoder for the Location URL in HTTP redirects.
	 */
	protected static URLEncoder urlEncoder;

	// ----------------------------------------------------- Static Initializer

	/**
	 * The safe character set.
	 */
	static {
		urlEncoder = new URLEncoder();
		urlEncoder.addSafeCharacter('-');
		urlEncoder.addSafeCharacter('_');
		urlEncoder.addSafeCharacter('.');
		urlEncoder.addSafeCharacter('*');
		urlEncoder.addSafeCharacter('/');
	}

	// -------------------------------------------------------- Adapter Methods

	/**
	 * Event method.
	 * 
	 * @return false to indicate an error, expected or not
	 */
	public boolean event(org.apache.coyote.Request req,
			org.apache.coyote.Response res, SocketStatus status) {

		Request request = (Request) req.getNote(ADAPTER_NOTES);
		Response response = (Response) res.getNote(ADAPTER_NOTES);

		if (request.getWrapper() != null) {

			boolean error = false;
			boolean read = false;
			try {
				if (status == SocketStatus.OPEN) {
					if (response.isClosed()) {
						// The event has been closed asynchronously, so call end
						// instead of
						// read to cleanup the pipeline
						request.getEvent().setEventType(
								CometEvent.EventType.END);
						request.getEvent().setEventSubType(null);
					} else {
						try {
							// Fill the read buffer of the servlet layer
							if (request.read()) {
								read = true;
							}
						} catch (IOException e) {
							error = true;
						}
						if (read) {
							request.getEvent().setEventType(
									CometEvent.EventType.READ);
							request.getEvent().setEventSubType(null);
						} else if (error) {
							request.getEvent().setEventType(
									CometEvent.EventType.ERROR);
							request.getEvent().setEventSubType(
									CometEvent.EventSubType.CLIENT_DISCONNECT);
						} else {
							request.getEvent().setEventType(
									CometEvent.EventType.END);
							request.getEvent().setEventSubType(null);
						}
					}
				} else if (status == SocketStatus.DISCONNECT) {
					request.getEvent().setEventType(CometEvent.EventType.ERROR);
					request.getEvent().setEventSubType(
							CometEvent.EventSubType.CLIENT_DISCONNECT);
					error = true;
				} else if (status == SocketStatus.ERROR) {
					request.getEvent().setEventType(CometEvent.EventType.ERROR);
					request.getEvent().setEventSubType(
							CometEvent.EventSubType.IOEXCEPTION);
					error = true;
				} else if (status == SocketStatus.STOP) {
					request.getEvent().setEventType(CometEvent.EventType.END);
					request.getEvent().setEventSubType(
							CometEvent.EventSubType.SERVER_SHUTDOWN);
				} else if (status == SocketStatus.TIMEOUT) {
					if (response.isClosed()) {
						// The event has been closed asynchronously, so call end
						// instead of
						// read to cleanup the pipeline
						request.getEvent().setEventType(
								CometEvent.EventType.END);
						request.getEvent().setEventSubType(null);
					} else {
						request.getEvent().setEventType(
								CometEvent.EventType.ERROR);
						request.getEvent().setEventSubType(
								CometEvent.EventSubType.TIMEOUT);
					}
				}

				req.getRequestProcessor().setWorkerThreadName(
						Thread.currentThread().getName());

				// Calling the container
				connector.getContainer().getPipeline().getFirst().event(
						request, response, request.getEvent());

				if (!error
						&& !response.isClosed()
						&& (request.getAttribute(Globals.EXCEPTION_ATTR) != null)) {
					// An unexpected exception occurred while processing the
					// event, so
					// error should be called
					request.getEvent().setEventType(CometEvent.EventType.ERROR);
					request.getEvent().setEventSubType(null);
					error = true;
					connector.getContainer().getPipeline().getFirst().event(
							request, response, request.getEvent());
				}
				if (response.isClosed() || !request.isComet()) {
					if (status == SocketStatus.OPEN) {
						// CometEvent.close was called during an event.
						request.getEvent().setEventType(
								CometEvent.EventType.END);
						request.getEvent().setEventSubType(null);
						error = true;
						connector.getContainer().getPipeline().getFirst()
								.event(request, response, request.getEvent());
					}
					res.action(ActionCode.ACTION_COMET_END, null);
				} else if (!error && read && request.getAvailable()) {
					// If this was a read and not all bytes have been read, or
					// if no data
					// was read from the connector, then it is an error
					request.getEvent().setEventType(CometEvent.EventType.ERROR);
					request.getEvent().setEventSubType(
							CometEvent.EventSubType.IOEXCEPTION);
					error = true;
					connector.getContainer().getPipeline().getFirst().event(
							request, response, request.getEvent());
				}
				return (!error);
			} catch (Throwable t) {
				if (!(t instanceof IOException)) {
					log.error(sm.getString("coyoteAdapter.service"), t);
				}
				error = true;
				return false;
			} finally {
				req.getRequestProcessor().setWorkerThreadName(null);
				// Recycle the wrapper request and response
				if (error || response.isClosed() || !request.isComet()) {
					request.recycle();
					request.setFilterChain(null);
					response.recycle();
				}
			}

		} else {
			return false;
		}
	}

	/**
	 * Service method.
	 */
	public void service(org.apache.coyote.Request req,
			org.apache.coyote.Response res) throws Exception {

		Request request = (Request) req.getNote(ADAPTER_NOTES);
		Response response = (Response) res.getNote(ADAPTER_NOTES);

		if (request == null) {

			// Create objects
			request = (Request) connector.createRequest();
			request.setCoyoteRequest(req);
			response = (Response) connector.createResponse();
			response.setCoyoteResponse(res);

			// Link objects
			request.setResponse(response);
			response.setRequest(request);

			// Set as notes
			req.setNote(ADAPTER_NOTES, request);
			res.setNote(ADAPTER_NOTES, response);

			// Set query string encoding
			req.getParameters().setQueryStringEncoding(
					connector.getURIEncoding());

		}

		if (connector.getXpoweredBy()) {
			response.addHeader("X-Powered-By", POWERED_BY);
		}

		boolean comet = false;

		try {

			// Parse and set Catalina and configuration specific
			// request parameters
			req.getRequestProcessor().setWorkerThreadName(
					Thread.currentThread().getName());
			if (postParseRequest(req, request, res, response)) {
				// Calling the container
				connector.getContainer().getPipeline().getFirst().invoke(
						request, response);

				if (request.isComet()) {
					if (!response.isClosed() && !response.isError()) {
						if (request.getAvailable()
								|| (request.getContentLength() > 0 && (!request
										.isParametersParsed()))) {
							// Invoke a read event right away if there are
							// available bytes
							if (event(req, res, SocketStatus.OPEN)) {
								comet = true;
								res.action(ActionCode.ACTION_COMET_BEGIN, null);
							}
						} else {
							comet = true;
							res.action(ActionCode.ACTION_COMET_BEGIN, null);
						}
					} else {
						// Clear the filter chain, as otherwise it will not be
						// reset elsewhere
						// since this is a Comet request
						request.setFilterChain(null);
					}
				}

			}

			if (!comet) {
				response.finishResponse();
				req.action(ActionCode.ACTION_POST_REQUEST, null);
			}

		} catch (IOException e) {
			;
		} catch (Throwable t) {
			log.error(sm.getString("coyoteAdapter.service"), t);
		} finally {
			req.getRequestProcessor().setWorkerThreadName(null);
			// Recycle the wrapper request and response
			if (!comet) {
				request.recycle();
				response.recycle();
			} else {
				// Clear converters so that the minimum amount of memory
				// is used by this processor
				request.clearEncoders();
				response.clearEncoders();
			}
		}

	}

	public void log(org.apache.coyote.Request req,
			org.apache.coyote.Response res, long time) {

		Request request = (Request) req.getNote(ADAPTER_NOTES);
		Response response = (Response) res.getNote(ADAPTER_NOTES);
		boolean create = false;

		if (request == null) {
			create = true;
			// Create objects
			request = connector.createRequest();
			request.setCoyoteRequest(req);
			response = connector.createResponse();
			response.setCoyoteResponse(res);

			// Link objects
			request.setResponse(response);
			response.setRequest(request);

			// Set as notes
			req.setNote(ADAPTER_NOTES, request);
			res.setNote(ADAPTER_NOTES, response);

			// Set query string encoding
			req.getParameters().setQueryStringEncoding(
					connector.getURIEncoding());
		}

		connector.getService().getContainer().logAccess(request, response,
				time, true);

		if (create) {
			request.recycle();
			response.recycle();
		}
	}

	// ------------------------------------------------------ Protected Methods

	/**
	 * Parse additional request parameters.
	 */
	protected boolean postParseRequest(org.apache.coyote.Request req,
			Request request, org.apache.coyote.Response res, Response response)
			throws Exception {

		// XXX the processor needs to set a correct scheme and port prior to
		// this point,
		// in ajp13 protocols dont make sense to get the port from the
		// connector..
		// XXX the processor may have set a correct scheme and port prior to
		// this point,
		// in ajp13 protocols dont make sense to get the port from the
		// connector...
		// otherwise, use connector configuration
		if (!req.scheme().isNull()) {
			// use processor specified scheme to determine secure state
			request.setSecure(req.scheme().equals("https"));
		} else {
			// use connector scheme and secure configuration, (defaults to
			// "http" and false respectively)
			req.scheme().setString(connector.getScheme());
			request.setSecure(connector.getSecure());
		}

		// FIXME: the code below doesnt belongs to here,
		// this is only have sense
		// in Http11, not in ajp13..
		// At this point the Host header has been processed.
		// Override if the proxyPort/proxyHost are set
		String proxyName = connector.getProxyName();
		int proxyPort = connector.getProxyPort();
		if (proxyPort != 0) {
			req.setServerPort(proxyPort);
		}
		if (proxyName != null) {
			req.serverName().setString(proxyName);
		}

		// Copy the raw URI to the decoded URI
		MessageBytes decodedURI = req.decodedURI();
		decodedURI.duplicate(req.requestURI());

		// Parse the path parameters. This will:
		// - strip out the path parameters
		// - convert the decodedURI to bytes
		parsePathParameters(req, request);

		// URI decoding
		// %xx decoding of the URL
		try {
			req.getURLDecoder().convert(decodedURI, false);
		} catch (IOException ioe) {
			res.setStatus(400);
			res.setMessage("Invalid URI: " + ioe.getMessage());
			connector.getService().getContainer().logAccess(request, response,
					0, true);
			return false;
		}
		// Normalization
		if (!normalize(req.decodedURI())) {
			res.setStatus(400);
			res.setMessage("Invalid URI");
			connector.getService().getContainer().logAccess(request, response,
					0, true);
			return false;
		}
		// Character decoding
		convertURI(decodedURI, request);
		// Check that the URI is still normalized
		if (!checkNormalize(req.decodedURI())) {
			res.setStatus(400);
			res.setMessage("Invalid URI character encoding");
			connector.getService().getContainer().logAccess(request, response,
					0, true);
			return false;
		}

		// Set the remote principal
		String principal = req.getRemoteUser().toString();
		if (principal != null) {
			request.setUserPrincipal(new CoyotePrincipal(principal));
		}

		// Set the authorization type
		String authtype = req.getAuthType().toString();
		if (authtype != null) {
			request.setAuthType(authtype);
		}

		// Request mapping.
		MessageBytes serverName;
		if (connector.getUseIPVHosts()) {
			serverName = req.localName();
			if (serverName.isNull()) {
				// well, they did ask for it
				res.action(ActionCode.ACTION_REQ_LOCAL_NAME_ATTRIBUTE, null);
			}
		} else {
			serverName = req.serverName();
		}
		connector.getMapper().map(serverName, decodedURI,
				request.getMappingData());
		request.setContext((Context) request.getMappingData().context);

		// If there is no context at this point, it is likely no ROOT context
		// has been deployed
		if (request.getContext() == null) {
			res.setStatus(404);
			res.setMessage("Not found");
			connector.getService().getContainer().logAccess(request, response,
					0, true);
			return false;
		}

		// Had to do this after the context was set.
		// Unfortunately parseSessionId is still necessary as it
		// affects the final URL. Safe as session cookies still
		// haven't been parsed.
		if (isURLRewritingDisabled(request))
			clearRequestedSessionURL(request);
		request.setWrapper((Wrapper) request.getMappingData().wrapper);

		// Filter trace method
		if (!connector.getAllowTrace()
				&& req.method().equalsIgnoreCase("TRACE")) {
			Wrapper wrapper = request.getWrapper();
			String header = null;
			if (wrapper != null) {
				String[] methods = wrapper.getServletMethods();
				if (methods != null) {
					for (int i = 0; i < methods.length; i++) {
						if ("TRACE".equals(methods[i])) {
							continue;
						}
						if (header == null) {
							header = methods[i];
						} else {
							header += ", " + methods[i];
						}
					}
				}
			}
			res.setStatus(405);
			res.addHeader("Allow", header);
			res.setMessage("TRACE method is not allowed");
			request.getContext().logAccess(request, response, 0, true);
			return false;
		}

		// Possible redirect
		MessageBytes redirectPathMB = request.getMappingData().redirectPath;
		if (!redirectPathMB.isNull()) {
			String redirectPath = urlEncoder.encode(redirectPathMB.toString());
			String query = request.getQueryString();
			if (request.isRequestedSessionIdFromURL()) {
				// This is not optimal, but as this is not very common, it
				// shouldn't matter
				redirectPath = redirectPath + ";"
						+ Globals.SESSION_PARAMETER_NAME + "="
						+ request.getRequestedSessionId();
			}
			if (query != null) {
				// This is not optimal, but as this is not very common, it
				// shouldn't matter
				redirectPath = redirectPath + "?" + query;
			}
			response.sendRedirect(redirectPath);
			request.getContext().logAccess(request, response, 0, true);
			return false;
		}

		// Parse session Id
		String sessionID = request
				.getPathParameter(Globals.SESSION_PARAMETER_NAME);
		if (sessionID != null) {
			request.setRequestedSessionId(sessionID);
			request.setRequestedSessionURL(true);
		}
		parseSessionCookiesId(req, request);

		return true;
	}

	private boolean isURLRewritingDisabled(Request request) {
		Context context = (Context) request.getMappingData().context;
		if (context != null)
			return (context.isDisableURLRewriting());
		else
			return (false);
	}

	/**
	 * Extract the path parameters from the request. This assumes parameters are
	 * of the form /path;name=value;name2=value2/ etc. Currently only really
	 * interested in the session ID that will be in this form. Other parameters
	 * can safely be ignored.
	 * 
	 * @param req
	 * @param request
	 */
	protected void parsePathParameters(org.apache.coyote.Request req,
			Request request) {

		// Process in bytes (this is default format so this is normally a NO-OP
		req.decodedURI().toBytes();

		ByteChunk uriBC = req.decodedURI().getByteChunk();
		int semicolon = uriBC.indexOf(';', 0);

		// What encoding to use? Some platforms, eg z/os, use a default
		// encoding that doesn't give the expected result so be explicit
		String enc = connector.getURIEncoding();
		if (enc == null) {
			enc = "ISO-8859-1";
		}

		if (log.isDebugEnabled()) {
			log.debug(sm.getString("coyoteAdapter.debug", "uriBC", uriBC
					.toString()));
			log.debug(sm.getString("coyoteAdapter.debug", "semicolon", String
					.valueOf(semicolon)));
			log.debug(sm.getString("coyoteAdapter.debug", "enc", enc));
		}

		boolean warnedEncoding = false;

		while (semicolon > -1) {
			// Parse path param, and extract it from the decoded request URI
			int start = uriBC.getStart();
			int end = uriBC.getEnd();

			int pathParamStart = semicolon + 1;
			int pathParamEnd = ByteChunk.findBytes(uriBC.getBuffer(), start
					+ pathParamStart, end, new byte[] { ';', '/' });

			String pv = null;

			if (pathParamEnd >= 0) {
				try {
					pv = (new String(uriBC.getBuffer(), start + pathParamStart,
							pathParamEnd - pathParamStart, enc));
				} catch (UnsupportedEncodingException e) {
					if (!warnedEncoding) {
						log.warn(sm.getString("coyoteAdapter.parsePathParam",
								enc));
						warnedEncoding = true;
					}
				}
				// Extract path param from decoded request URI
				byte[] buf = uriBC.getBuffer();
				for (int i = 0; i < end - start - pathParamEnd; i++) {
					buf[start + semicolon + i] = buf[start + i + pathParamEnd];
				}
				uriBC.setBytes(buf, start, end - start - pathParamEnd
						+ semicolon);
			} else {
				try {
					pv = (new String(uriBC.getBuffer(), start + pathParamStart,
							(end - start) - pathParamStart, enc));
				} catch (UnsupportedEncodingException e) {
					if (!warnedEncoding) {
						log.warn(sm.getString("coyoteAdapter.parsePathParam",
								enc));
						warnedEncoding = true;
					}
				}
				uriBC.setEnd(start + semicolon);
			}

			if (log.isDebugEnabled()) {
				log.debug(sm.getString("coyoteAdapter.debug", "pathParamStart",
						String.valueOf(pathParamStart)));
				log.debug(sm.getString("coyoteAdapter.debug", "pathParamEnd",
						String.valueOf(pathParamEnd)));
				log.debug(sm.getString("coyoteAdapter.debug", "pv", pv));
			}

			if (pv != null) {
				int equals = pv.indexOf('=');
				if (equals > -1) {
					String name = pv.substring(0, equals);
					String value = pv.substring(equals + 1);
					request.addPathParameter(name, value);
					if (log.isDebugEnabled()) {
						log.debug(sm.getString("coyoteAdapter.debug", "equals",
								String.valueOf(equals)));
						log.debug(sm.getString("coyoteAdapter.debug", "name",
								name));
						log.debug(sm.getString("coyoteAdapter.debug", "value",
								value));
					}
				}
			}

			semicolon = uriBC.indexOf(';', semicolon);
		}
	}

	/**
	 * Parse session id in URL.
	 * 
	 * @deprecated Not used since 6.0.30
	 */
	@Deprecated
	protected void parseSessionId(org.apache.coyote.Request req, Request request) {

		parsePathParameters(req, request);

		String sessionID = request
				.getPathParameter(Globals.SESSION_PARAMETER_NAME);
		if (sessionID != null) {
			request.setRequestedSessionId(sessionID);
			request.setRequestedSessionURL(true);
		} else {
			clearRequestedSessionURL(request);
		}

	}

	private void clearRequestedSessionURL(Request request) {
		request.setRequestedSessionId(null);
		request.setRequestedSessionURL(false);
	}

	/**
	 * Parse session id in URL.
	 */
	protected void parseSessionCookiesId(org.apache.coyote.Request req,
			Request request) {

		// If session tracking via cookies has been disabled for the current
		// context, don't go looking for a session ID in a cookie as a cookie
		// from a parent context with a session ID may be present which would
		// overwrite the valid session ID encoded in the URL
		Context context = (Context) request.getMappingData().context;
		if (context != null && !context.getCookies())
			return;

		// Parse session id from cookies
		Cookies serverCookies = req.getCookies();
		int count = serverCookies.getCookieCount();
		if (count <= 0)
			return;

		String sessionCookieName = getSessionCookieName(context);

		for (int i = 0; i < count; i++) {
			ServerCookie scookie = serverCookies.getCookie(i);
			if (scookie.getName().equals(sessionCookieName)) {
				// Override anything requested in the URL
				if (!request.isRequestedSessionIdFromCookie()) {
					// Accept only the first session id cookie
					convertMB(scookie.getValue());
					request
							.setRequestedSessionId(scookie.getValue()
									.toString());
					request.setRequestedSessionCookie(true);
					request.setRequestedSessionURL(false);
					if (log.isDebugEnabled())
						log.debug(" Requested cookie session id is "
								+ request.getRequestedSessionId());
				} else {
					if (!request.isRequestedSessionIdValid()) {
						// Replace the session id until one is valid
						convertMB(scookie.getValue());
						request.setRequestedSessionId(scookie.getValue()
								.toString());
					}
				}
			}
		}

	}

	/**
	 * Character conversion of the URI.
	 */
	protected void convertURI(MessageBytes uri, Request request)
			throws Exception {

		ByteChunk bc = uri.getByteChunk();
		int length = bc.getLength();
		CharChunk cc = uri.getCharChunk();
		cc.allocate(length, -1);

		String enc = connector.getURIEncoding();
		if (enc != null) {
			B2CConverter conv = request.getURIConverter();
			try {
				if (conv == null) {
					conv = new B2CConverter(enc);
					request.setURIConverter(conv);
				}
			} catch (IOException e) {
				// Ignore
				log.error("Invalid URI encoding; using HTTP default");
				connector.setURIEncoding(null);
			}
			if (conv != null) {
				try {
					conv.convert(bc, cc);
					uri.setChars(cc.getBuffer(), cc.getStart(), cc.getLength());
					return;
				} catch (IOException e) {
					log.error("Invalid URI character encoding; trying ascii");
					cc.recycle();
				}
			}
		}

		// Default encoding: fast conversion
		byte[] bbuf = bc.getBuffer();
		char[] cbuf = cc.getBuffer();
		int start = bc.getStart();
		for (int i = 0; i < length; i++) {
			cbuf[i] = (char) (bbuf[i + start] & 0xff);
		}
		uri.setChars(cbuf, 0, length);

	}

	/**
	 * Character conversion of the a US-ASCII MessageBytes.
	 */
	protected void convertMB(MessageBytes mb) {

		// This is of course only meaningful for bytes
		if (mb.getType() != MessageBytes.T_BYTES)
			return;

		ByteChunk bc = mb.getByteChunk();
		CharChunk cc = mb.getCharChunk();
		int length = bc.getLength();
		cc.allocate(length, -1);

		// Default encoding: fast conversion
		byte[] bbuf = bc.getBuffer();
		char[] cbuf = cc.getBuffer();
		int start = bc.getStart();
		for (int i = 0; i < length; i++) {
			cbuf[i] = (char) (bbuf[i + start] & 0xff);
		}
		mb.setChars(cbuf, 0, length);

	}

	/**
	 * Normalize URI.
	 * <p>
	 * This method normalizes "\", "//", "/./" and "/../". This method will
	 * return false when trying to go above the root, or if the URI contains a
	 * null byte.
	 * 
	 * @param uriMB
	 *            URI to be normalized
	 */
	public static boolean normalize(MessageBytes uriMB) {

		ByteChunk uriBC = uriMB.getByteChunk();
		final byte[] b = uriBC.getBytes();
		final int start = uriBC.getStart();
		int end = uriBC.getEnd();

		// An empty URL is not acceptable
		if (start == end)
			return false;

		// URL * is acceptable
		if ((end - start == 1) && b[start] == (byte) '*')
			return true;

		int pos = 0;
		int index = 0;

		// Replace '\' with '/'
		// Check for null byte
		for (pos = start; pos < end; pos++) {
			if (b[pos] == (byte) '\\') {
				if (ALLOW_BACKSLASH) {
					b[pos] = (byte) '/';
				} else {
					return false;
				}
			}
			if (b[pos] == (byte) 0) {
				return false;
			}
		}

		// The URL must start with '/'
		if (b[start] != (byte) '/') {
			return false;
		}

		// Replace "//" with "/"
		for (pos = start; pos < (end - 1); pos++) {
			if (b[pos] == (byte) '/') {
				while ((pos + 1 < end) && (b[pos + 1] == (byte) '/')) {
					copyBytes(b, pos, pos + 1, end - pos - 1);
					end--;
				}
			}
		}

		// If the URI ends with "/." or "/..", then we append an extra "/"
		// Note: It is possible to extend the URI by 1 without any side effect
		// as the next character is a non-significant WS.
		if (((end - start) >= 2) && (b[end - 1] == (byte) '.')) {
			if ((b[end - 2] == (byte) '/')
					|| ((b[end - 2] == (byte) '.') && (b[end - 3] == (byte) '/'))) {
				b[end] = (byte) '/';
				end++;
			}
		}

		uriBC.setEnd(end);

		index = 0;

		// Resolve occurrences of "/./" in the normalized path
		while (true) {
			index = uriBC.indexOf("/./", 0, 3, index);
			if (index < 0)
				break;
			copyBytes(b, start + index, start + index + 2, end - start - index
					- 2);
			end = end - 2;
			uriBC.setEnd(end);
		}

		index = 0;

		// Resolve occurrences of "/../" in the normalized path
		while (true) {
			index = uriBC.indexOf("/../", 0, 4, index);
			if (index < 0)
				break;
			// Prevent from going outside our context
			if (index == 0)
				return false;
			int index2 = -1;
			for (pos = start + index - 1; (pos >= 0) && (index2 < 0); pos--) {
				if (b[pos] == (byte) '/') {
					index2 = pos;
				}
			}
			copyBytes(b, start + index2, start + index + 3, end - start - index
					- 3);
			end = end + index2 - index - 3;
			uriBC.setEnd(end);
			index = index2;
		}

		return true;

	}

	/**
	 * Check that the URI is normalized following character decoding.
	 * <p>
	 * This method checks for "\", 0, "//", "/./" and "/../". This method will
	 * return false if sequences that are supposed to be normalized are still
	 * present in the URI.
	 * 
	 * @param uriMB
	 *            URI to be checked (should be chars)
	 */
	public static boolean checkNormalize(MessageBytes uriMB) {

		CharChunk uriCC = uriMB.getCharChunk();
		char[] c = uriCC.getChars();
		int start = uriCC.getStart();
		int end = uriCC.getEnd();

		int pos = 0;

		// Check for '\' and 0
		for (pos = start; pos < end; pos++) {
			if (c[pos] == '\\') {
				return false;
			}
			if (c[pos] == 0) {
				return false;
			}
		}

		// Check for "//"
		for (pos = start; pos < (end - 1); pos++) {
			if (c[pos] == '/') {
				if (c[pos + 1] == '/') {
					return false;
				}
			}
		}

		// Check for ending with "/." or "/.."
		if (((end - start) >= 2) && (c[end - 1] == '.')) {
			if ((c[end - 2] == '/')
					|| ((c[end - 2] == '.') && (c[end - 3] == '/'))) {
				return false;
			}
		}

		// Check for "/./"
		if (uriCC.indexOf("/./", 0, 3, 0) >= 0) {
			return false;
		}

		// Check for "/../"
		if (uriCC.indexOf("/../", 0, 4, 0) >= 0) {
			return false;
		}

		return true;

	}

	/**
	 * Copy an array of bytes to a different position. Used during
	 * normalization.
	 */
	protected static void copyBytes(byte[] b, int dest, int src, int len) {
		for (int pos = 0; pos < len; pos++) {
			b[pos + dest] = b[pos + src];
		}
	}

	private String getSessionCookieName(Context context) {

		String result = null;

		if (context != null) {
			result = context.getSessionCookieName();
		}

		if (result == null) {
			result = Globals.SESSION_COOKIE_NAME;
		}

		return result;
	}
}
